1. Field of the Invention
The present invention relates to an adjustable drill guide for accurate tibial tunnel placement both inside and outside the knee in endoscopic ACL reconstruction and, more specifically, to a drill guide which can be used with a plurality of different marking hooks.
2. Description of the Related Art
In the past, the intra-articular entry point of the tibial tunnel has tended to be placed too far anterior, resulting in roof impingement and delayed graft failure. See, e.g., S. Howell, "A Rationale for Predicting ACL Graft Inpingement by the Intercondylar Roof, A Magnetic Resonance Imaging Study", Am. Jour. Sports Med., Vol. 19, No., pp. 276 (1991), herein incorporated by reference. This problem has occurred largely due to the absence of any constant bony landmarks in the intercondylar notch which can be used to orient placement of guide systems for accurate reproducible tibial tunnel guide pin placement.
Also, the tibial tunnel exit point outside the knee has tended to be placed too close to the joint line. This results in a short tibial tunnel such that the tibial bone plug of a completed bone patellar tendon bone autograft reconstruction resides outside the tibial tunnel and interference screw fixation cannot be used. A second problem caused by a high tibial tunnel exit point is that the angle of the tibial tunnel in reference to the joint line is too small, which will not allow transtibial tunnel instrumentation to reach the isometric area on the lateral femoral condyle to create a femoral socket for graft fixation.